How do you solve #(x + 4)^2 = 81# using the square root property?

1 Answer
Aug 13, 2015

Answer:

The solutions are
#color(blue)(x=5, x=-13#

Explanation:

The square root property involves taking the square root of both the terms on either side of the equation.

Applying the same to the given equation:

#sqrt((x+4)^2)=sqrt(81#

(#sqrt81= color(blue)(+-9#)

So,
#sqrt((x+4)^2)=color(blue)(+-9#

#(x+4)=color(blue)(+-9#

Solution 1:
#x+4 = +9#
Isolating #x#
#x+4 -color(blue)(4)= +9-color(blue)(4)#
#color(blue)(x=5#

Solution 2:
#x+4 = -9#
Isolating #x#
#x+4 -color(blue)(4)= -9-color(blue)(4)#
#color(blue)(x=-13#